Lock & Key Terms Explained
This glossary covers 30+ essential locksmith terms from ANSI grades to transponder keys. Whether you're dealing with a lockout, considering a rekey, or upgrading to smart locks, these definitions help you communicate clearly with locksmiths and make informed decisions.
A rating system established by the American National Standards Institute that classifies lock strength and durability. Grade 1 is the highest (commercial), Grade 2 is for residential heavy-duty use, and Grade 3 is for basic residential.
A specially cut key that can be used to open pin tumbler locks through a technique called "bumping." Security-conscious homeowners should consider bump-resistant locks.
The part of a lock that contains the keyhole and internal mechanism (pins, wafers, or discs). Cylinders can often be replaced or rekeyed without changing the entire lock.
A lock bolt that is moved by turning a key or thumb turn, rather than by spring action. Deadbolts provide stronger security than spring-loaded latches because they cannot be pushed back without the key.
A deadbolt that requires a key to open from both inside and outside. Provides extra security but may pose a fire safety concern as occupants need a key to exit.
The process of creating a copy of an existing key. Not all keys can be duplicated—some are restricted or require authorization.
A lock that uses an electric current to control the locking mechanism. May include keypads, card readers, or biometric scanners.
A situation where someone is locked out of their home, car, or business and needs immediate locksmith assistance to regain entry.
The process of removing a broken key from a lock cylinder using specialized tools. Proper extraction prevents damage to the lock.
Locks designed to resist picking, drilling, bumping, and other bypass methods. Often feature restricted keyways, reinforced materials, and anti-drill protection.
An electronic security device in vehicles that prevents the engine from starting unless the correct transponder key is present. Most cars made after 1998 have immobilizers.
An uncut key that has the correct shape to fit into a specific lock but has not yet been cut to operate that lock.
The process of shaping a key blank to match a specific lock pattern. Can be done by code (from a number) or by duplication (from an existing key).
A small, handheld remote device that communicates wirelessly with a vehicle to lock/unlock doors and often start the engine. Modern fobs use rolling codes for security.
The specific shape of the key slot in a lock. Locks with different keyways cannot accept each other's keys, adding a layer of security.
Professional assistance to gain entry when locked out of a home, car, or business. Legitimate locksmiths use non-destructive methods whenever possible.
A hierarchical key system where individual keys open specific locks, but a master key can open all locks in the system. Common in commercial and multi-unit residential buildings.
A lock that fits into a pocket (mortise) cut into the door edge. More complex than cylindrical locks, mortise locks are often found in commercial buildings and older homes.
A portable lock with a shackle that passes through an opening to secure gates, chains, lockers, or sheds. Available in combination and keyed versions.
The most common lock type, using spring-loaded pins of varying lengths. When the correct key is inserted, pins align at the shear line, allowing the cylinder to rotate.
A key fob or card that unlocks doors when brought near the vehicle, without pressing buttons. Also enables push-button start in many vehicles.
Changing the internal pins of a lock so that old keys no longer work and new keys are required. Cheaper than replacing locks and ideal after moving into a new home.
A key that cannot be duplicated without proper authorization. The key blank is controlled and only available to authorized dealers.
The process of opening a safe without the combination or key. Professional locksmiths use various methods including manipulation, drilling, or electronic decoding.
The U-shaped bar of a padlock that passes through an opening to secure it. Hardened steel shackles resist cutting attacks.
A deadbolt with a key cylinder on the outside and a thumb turn on the inside. The most common residential deadbolt type.
An electronic lock that can be controlled via smartphone, voice commands, or home automation systems. Often includes features like remote access, activity logs, and temporary codes.
The metal plate attached to the door frame that the bolt extends into. Reinforced strike plates with longer screws significantly improve kick-in resistance.
A car key with an embedded microchip that communicates with the vehicle's immobilizer. The engine will not start unless the correct transponder signal is received.
A lock with a circular keyway and pins arranged in a circle, commonly found on vending machines, bike locks, and some computer locks.
Vehicle Identification Number—a unique 17-character code identifying a specific vehicle. Locksmiths use the VIN to cut keys by code when no original key exists.
A lock using flat wafers instead of pins. Common in automotive door locks, filing cabinets, and some padlocks. Generally less secure than pin tumbler locks.
Last updated: 2025-12-10
